The steps related to the installation of the French drain

Are you in the process of planning a french drain installation and would like to know how it’s going to go? What to check for while the professionals are working on it? 

At Groupe Durasec, we want our partners and clients to be well informed about the process of installing a french drain and we would like to take you on a tour of every step that will happen in the process. This way, you will know exactly how the installation will affect your time and what to check to make sure everything goes smoothly.

A clear and personalized diagnosis

To find out how to install a French drain and get the facts about the situation, it is recommended to call on a team of experts such as Groupe Durasec. If the verdict suggests a drain replacement, excavation will have to be carried out.

Determining the location of the collection tank, the place where the water will be routed and the positioning of the access chimneys

As a drainage contractor, one of the first steps will be to determine the best way to evacuate the water coming from the French drain. We advise you to select an indoor tank or an outdoor pumping station where the water can be evacuated by gravity. You could also use a pumping method to transport the water to a higher point, hence the term “lift pump” or “submersible pump” (commonly referred to as a sump pump). 

Before starting the excavation work, we go around the land and select the place where the collected water can flow, without damaging the neighboring properties, if the option to exit the water through the surface is selected. Normally, excess water is redirected to the street, to a ditch (in rural situations) or to a storm drain. Sometimes there is no other option but to send the water down the drain. In this specific case, we say that the sewer is mixed and that water inflows from the French drain are tolerated. The urban planners of each of the municipalities take charge of these restrictions.

Since pressure washers clean by moving backwards, the positioning of the chimneys will dictate the exit point (catchment tank or interior pumping station).

Excavation work

Excavation work is an operation that requires a lot of attention to detail. This consists of clearing the foundations by creating a trench that goes around the building.

To complete this step, a location request to Info-Excavation must be made by our company. Once on site, it’s important to be very careful not to damage the various pipes and wires that are underground. 

The various instances that offer you services, such as water pipes, telecommunications or electricity wires, are located very close to your property. It would be a shame and very expensive to hit one with the mechanical shovel.

We recommend digging a trench about 24 inches wide at the base, to have a large quantity of clean ¾ stone on the drain. The width of the excavation at the height of the grass, asphalt or other will be determined according to depth. 

You must add 2 feet to the excavation depth in order to calculate the width of the ground that will be excavated from the foundation wall of your house. It should be noted that a slope of 45 degrees is required to comply with the standards of the Commission for Standards, Equity, Health and Safety at Work (CNESST).

Installation of a geotextile membrane

While following the manufacturer’s instructions, it is now time to install a geotextile membrane on the gravel bottom. We will voluntarily leave a good amount of tissue sticking out, this way we can fold the excess over the drain. This installation will enhance the protection offered by the French drain.

After properly laying the waterproofing membrane at the bottom of the trench, we can now lay the French drain there and connect it to the sump, sewer or outdoor pumping station.

Covering the French drain

Once the drain is connected to the sewers, all that is left to do is cover it. Using washed gravel (¾ net), it is recommended to put in place a good 12 inches thick. A second section of geotextile will be installed on top of the stone to prevent contamination by fine particles from the earth fill. This will provide effective drainage for many years.

Foundation washing, diamond grinding and cavity filling

Surface preparation is the crucial step for the membrane to adhere perfectly to the substrate. A jet of water using 3,500 lbs of pressure will be necessary to dislodge the dirt present on the surface of the concrete. Following this washing operation, grinding with a diamond blade will be carried out. A visual examination will show us the cavities that will be filled with hydraulic concrete later.

Hot spraying of 3 cross coats of the RUB-R-WALL membrane and installation of the GEO-WRAP drainage panel

As the title suggests, a horizontal, then vertical and then horizontal layer of RUB-R-WALL polymer will be sprayed on the concrete from the footing up to the final height that we want to obtain in order to build the ultimate waterproofing protection (laboratory tested to provide a minimum lifespan of 100 years). 

The effect of moisture transfer through the concrete will be impossible in the long term, and this is really what you, as a customer, are looking for to avoid mold contamination in your basement.

Note that the drying time between coats is relative to the outside temperature, because as soon as the temperature of the product drops, the consistency of the rubberized membrane takes shape.

The second element of the double membrane system is the GEO-WRAP drainage panel. Its function is to convey the water contained in the ground (thereby reducing the pressure of the frozen ground in winter) to the French drain and to provide a small protection to the RUB-R-WALL membrane. It will be fixed with treated nails, which are protected from corrosion.

The RUB-R-WALL double membrane system offers a 25-year warranty, including time and material.

Completely filling the trench

To finalize the work, all that remains is to fill the trench with the excavation soil until the height of the original ground level is reached or raised to correct the previously negative slope. It can also be reduced if the slope was once too steep and you want to give your property a whole new visual effect.

As you can see, installing a French drain is no small feat. As there are several elements to take into consideration or to pay particular attention to, we recommend that you hire a team that has the qualifications and certifications required to carry out this project.

But after all this work, you will be sure that your new French Drain will eliminate drainage problems, prevent issues caused by heavy rain and water pools formed around the house and prevent any health issues or damages caused by mold and moisture.

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questions ?

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